A new study on breast cancer survivors and published in the journal Cancer shows substantial protective benefits of physical activity on cognition.
It is well-established that increased levels of physical exercise can improve cognitive function among both healthy and impaired adult populations, but little research has been performed up to this point on the role of exercise in improving cognition in cancer survivors.
The work is an important breakthrough as there are very few treatments at present for cancer-related cognitive deficits. The problem is also widespread, with an estimated 80-85% of breast cancer survivors experiencing some form of cognitive problem.
Quality of life interventions aimed at improving invasive breast cancer outcomes is a priority for researchers across the world and in the United States, where an estimated quarter of a million new diagnoses are made each year. This is higher still than the number of prostate cancer diagnoses, the next most commonly diagnosed malignancy.
Exploring the Link Between Breast Cancer & Cognitive Problems
- Factors known to affect cognition include sleep problems, depression/anxiety, pain (and the side effects of pain medication), and comorbid physical illnesses.
- It has been shown that 0.5 years – 10 years post-treatment, breast cancer survivors treated with chemotherapy have poorer cognitive performance on average than those that haven’t received chemotherapy.
- Although depression, anxiety and/or fatigue can exacerbate cognitive problems, these issues alone don’t explain all of the deficit faced by breast cancer patients. Around 1 in 4 patients show a worse than expected cognitive performance that is not related to depression, anxiety or fatigue before receiving cancer treatment.
- Possible reasons for this include the existence of a risk factor that predisposes individuals to both the development of breast cancer and early cognitive decline or a link between cancer-related DNA damage to cognitive performance.
How the Study was Performed
A 12-week physical activity plan was assigned at random to 43 members of a group of 87 breast cancer survivors. The control arm of the study contained the remaining 44 women. All 87 individuals were deemed to be sedentary before the start of the trial.
The average age of participants was 57 and the average time since surgery was 2.5 years.
“Objective cognition” was gauged at baseline and after 12 weeks using the NIH Cognitive Toolbox and self-reported cognition was measured using the PROMIS scales.
The Results
Women participating in the exercise arm of the study saw twice as much improvement in tests of processing speed when compared to the control group.
Time since surgery, however, was a major factor in these observed differences. When limiting the study to women under two years post-surgery, researchers found the exercise group showed four times greater improvement in processing speed compared to the control group. Meanwhile, no significant improvement was present between the groups for women more than two years post-surgery.
Overall, the researchers observed a significant correlation between the amount of exercise performed and the extent of improvements in both objective and self-reported cognition. This suggests that more may be better when it comes to physical activity, although further research is needed before an optimal amount can be identified. Nevertheless, the participants in the exercise program averaged an increase 0f 100 minutes per week of extra physical activity compared to their tally before the study started.
Despite administering tests for numerous aspects of cognition, researchers only unearthed significant improvements in processing speed among the exercise group. Self-reported cognitive ability improvements were higher among this group too, but it is unclear whether exercise has beneficial effects on other aspects of cognition besides processing speed.
Bottom Line
If you or a loved one is a breast cancer patient, then you’ll be wondering how this study relates to you and how you can use its findings to improve cognition.
We know that slowed processing speed can lower functioning and so the improvements identified by the study are exciting. However, it appears that the best advice is to start early. The greatest benefits of exercise in this area are found in the first two years after surgery.
It is also well-established that the benefits of exercise go well beyond improved cognition. Nevertheless, it’s important to understand your limitations. Consult your doctor before starting a new exercise regimen, and remember to start slowly and build up as you develop your fitness!
Here’s some useful exercise advice tailored to women living with breast cancer:
Exercise Tips for Breast Cancer Patients
